Can still be used? Yes
The Faerie Paint Brush turns your pet into a Faerie. Common traits of Faerie Pets are delicate wings, unique patterns and soft colours.
To use the paint brush, you must take your pet and the item to the Rainbow Pool.
Do not confuse it with the Faerie Brush Plushie. Some tricky users might try to fool you into buying the plushie rather than the real thing, or you may simply buy the plushie by accident.
For a list of all Faerie neopets, go to Faerie (style).